Selgitage kohaliku võtme tööpõhimõtet andmebaasides.

Locally in databases, a key (local key) is a field or set of fields in a single table used to establish a relationship with another table. Usually, the local key is the primary key of the current table, which is referenced by a foreign key from another table.

The principle of operation of the local key is that it uniquely identifies a record in its table and serves as a point of connection for establishing relationships between tables. For example, if you have a "Users" table with a field "id" (local key), and an "Orders" table with a field "user_id" (foreign key), then "user_id" references "id" in the "Users" table.

In the context of Flutter and local databases (e.g., SQLite), the local key helps to efficiently link data and ensure data integrity during queries and updates.